:root {
  color-scheme: light;
  --ink: #25283a;
  --muted: #657087;
  --purple: #7651ad;
  --purple-soft: #f3effa;
  --gold-soft: #fff4bf;
  --line: #e5e1ec;
  --paper: #fffefb;
  --ground: #f5f3f8;
}

* { box-sizing: border-box; }

html { background: var(--ground); }

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 8% 0%, rgba(185, 164, 221, .22), transparent 29rem),
    var(--ground);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
  -webkit-font-smoothing: antialiased;
}

a { color: #55428b; text-underline-offset: .2em; }
a:focus-visible { outline: 3px solid #8468c0; outline-offset: 4px; }

.site-header {
  min-height: 64px;
  padding: 14px max(20px, calc((100vw - 980px) / 2));
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  border-bottom: 1px solid rgba(93, 76, 132, .14);
  background: rgba(255, 255, 255, .84);
  backdrop-filter: blur(12px);
}

.brand { color: var(--ink); font-size: 14px; font-weight: 700; text-decoration: none; }
.preview-badge { color: #64527e; font-size: 11px; letter-spacing: .08em; }

main { padding: clamp(28px, 6vw, 76px) 18px; }

.lesson {
  width: min(100%, 760px);
  margin: 0 auto;
  overflow: hidden;
  border: 1px solid rgba(98, 80, 135, .13);
  border-radius: 24px;
  background: var(--paper);
  box-shadow: 0 24px 70px rgba(46, 39, 66, .09);
}

.lesson-header {
  padding: clamp(34px, 7vw, 68px) clamp(22px, 7vw, 70px) 36px;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(155deg, #fff 0%, #faf7ff 65%, #f4f0fb 100%);
}

.lesson-id { margin: 0 0 15px; color: var(--purple); font-size: 12px; font-weight: 800; letter-spacing: .15em; }

h1 {
  max-width: 15em;
  margin: 0;
  font-family: "Yu Mincho", "Hiragino Mincho ProN", serif;
  font-size: clamp(31px, 6vw, 52px);
  font-weight: 600;
  line-height: 1.38;
  letter-spacing: .015em;
  text-wrap: balance;
}

.future-lead { margin: 24px 0 0; color: #4b5265; font-size: 16px; line-height: 1.9; }

.reading-guide {
  margin-top: 28px;
  padding: 16px 18px;
  display: grid;
  gap: 4px;
  border-left: 4px solid #9478c7;
  background: rgba(240, 234, 250, .7);
  font-size: 14px;
  line-height: 1.75;
}

.reading-guide strong { color: #5b477b; font-size: 12px; letter-spacing: .08em; }

.lesson-body { padding: 40px clamp(22px, 7vw, 70px) 18px; font-size: 17px; line-height: 1.95; }
.lesson-body p { margin: 0 0 22px; overflow-wrap: anywhere; }

.lesson-body h2 {
  margin: 58px 0 24px;
  color: #27283b;
  font-family: "Yu Mincho", "Hiragino Mincho ProN", serif;
  font-size: clamp(23px, 4vw, 29px);
  font-weight: 600;
  line-height: 1.55;
}

.lesson-body h2 span {
  background: linear-gradient(transparent 67%, rgba(190, 166, 230, .45) 67%, rgba(190, 166, 230, .45) 91%, transparent 91%);
  -webkit-box-decoration-break: clone;
  box-decoration-break: clone;
}

.lead-question {
  margin: 28px 0 26px !important;
  color: #514065;
  font-family: "Yu Mincho", "Hiragino Mincho ProN", serif;
  font-size: 21px;
  line-height: 1.8 !important;
}

.reader-voice {
  padding: 18px 20px;
  border: 1px solid #dfd5ee;
  border-radius: 10px;
  background: var(--purple-soft);
}

.insight {
  padding: 20px 22px;
  border-left: 4px solid #5d82b9;
  background: #eff5fb;
  color: #2e4669;
  font-weight: 700;
}

mark {
  color: inherit;
  background: linear-gradient(transparent 56%, rgba(255, 227, 112, .48) 56%);
}

.questions {
  margin: 24px 0 26px;
  padding: 0;
  list-style: none;
  counter-reset: question;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fff;
}

.questions li {
  position: relative;
  padding: 17px 20px 17px 58px;
  counter-increment: question;
}

.questions li + li { border-top: 1px solid var(--line); }
.questions li::before { content: counter(question); position: absolute; left: 20px; color: var(--purple); font-weight: 800; }

.source { margin-top: 38px !important; color: var(--muted); font-size: 13px; line-height: 1.8 !important; }

.lesson-footer { padding: 30px clamp(22px, 7vw, 70px) 42px; border-top: 1px solid var(--line); }
.lesson-footer p { margin: 0; }
.lesson-footer .author { margin-top: 9px; color: var(--muted); font-size: 14px; }

.site-footer { padding: 28px 20px 46px; color: var(--muted); font-size: 12px; line-height: 1.8; text-align: center; }
.site-footer p { margin: 0; }

.home-hero, .home-lessons, .home-action { width: min(100%, 760px); margin-inline: auto; }
.home-hero { padding: clamp(38px, 8vw, 86px) clamp(22px, 7vw, 70px); border: 1px solid rgba(98, 80, 135, .13); border-radius: 24px; background: linear-gradient(155deg, #fff 0%, #faf7ff 65%, #f4f0fb 100%); box-shadow: 0 24px 70px rgba(46, 39, 66, .09); }
.home-eyebrow { margin: 0 0 16px; color: var(--purple); font-size: 12px; font-weight: 800; letter-spacing: .15em; }
.home-hero h1 { max-width: 14em; }
.home-lead { margin: 24px 0 0; color: #4b5265; font-size: 17px; line-height: 1.9; }
.home-body { margin-top: 28px; padding: 16px 18px; border-left: 4px solid #9478c7; background: rgba(240, 234, 250, .7); font-size: 14px; line-height: 1.75; }
.home-body p { margin: 0; }
.home-lessons { display: grid; gap: 14px; margin-top: 28px; }
.lesson-card { display: grid; gap: 7px; padding: 24px 26px; border: 1px solid var(--line); border-radius: 16px; background: var(--paper); color: inherit; text-decoration: none; box-shadow: 0 12px 30px rgba(46, 39, 66, .05); transition: transform .16s ease, box-shadow .16s ease; }
.lesson-card:hover { transform: translateY(-2px); box-shadow: 0 18px 38px rgba(46, 39, 66, .10); }
.lesson-card-kind { color: var(--purple); font-size: 11px; font-weight: 800; letter-spacing: .1em; }
.lesson-card strong { font-family: "Yu Mincho", "Hiragino Mincho ProN", serif; font-size: 21px; line-height: 1.55; }
.lesson-card > span:last-child { color: var(--muted); font-size: 14px; line-height: 1.7; }
.home-action { margin-top: 34px; text-align: center; }
.text-link { display: inline-block; color: #55428b; font-weight: 700; text-decoration: none; }
.text-link::after { content: " →"; }
.roadmap-steps { display: grid; gap: 12px; margin: 0; padding: 0; list-style: none; }
.roadmap-steps li { display: grid; gap: 4px; padding: 15px 16px 15px 20px; border-left: 3px solid #9478c7; background: rgba(255, 255, 255, .74); }
.roadmap-steps strong { color: #55428b; }
.roadmap-steps span { color: #4b5265; font-size: 14px; line-height: 1.65; }

@media (max-width: 520px) {
  .site-header { min-height: 56px; }
  .brand { font-size: 12px; }
  .preview-badge { font-size: 9px; }
  main { padding: 16px 10px 32px; }
  .lesson { border-radius: 16px; }
  .lesson-header { padding: 34px 20px 28px; }
  h1 { font-size: 30px; line-height: 1.45; }
  .future-lead { font-size: 15px; }
  .lesson-body { padding: 32px 20px 12px; font-size: 16px; line-height: 1.9; }
  .lesson-body p { margin-bottom: 21px; }
  .lesson-body h2 { margin-top: 48px; font-size: 23px; }
  .lead-question { font-size: 19px; }
  .reader-voice, .insight { padding: 16px; }
  .questions li { padding: 15px 14px 15px 48px; }
  .questions li::before { left: 17px; }
  .home-hero { border-radius: 16px; padding: 36px 20px; }
  .home-lead { font-size: 16px; }
  .lesson-card { padding: 20px; }
  .lesson-card strong { font-size: 19px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; }
}